November 13, 2012

Girls With Stressed Mothers Grow Up To Be Stressed Teenagers

Researchers from the University of Wisconsin-Madison recently discovered that early family stress during infancy could be related to changes that occur in the daily brain function and anxiety of teenage girls.

The data was pooled from a population study that looked at the relationship between stress and the developmental pathway of the brain. For female infants who lived in homes with stressed out mothers, they were more likely to have higher levels of cortisol, a stress hormone, in preschool than other children of the same age. In particular, the researchers believed that elevated levels of cortisol and changes in brain activity could be preliminary factors for increased levels of anxiety for teens at 18 years of age. While these results were seen with girls in the study, the researchers did not see the same patterns with the male participants of the study. The research findings were recently published in Nature Neuroscience.

"We wanted to understand how stress early in life impacts patterns of brain development which might lead to anxiety and depression," explained the study´s first author Cory Burghy, a researcher at the Waisman Laboratory for Brain Imaging and Behavior at the University of Wisconsin-Madison, in a prepared statement. "Young girls who, as preschoolers, had heightened cortisol levels, go on to show lower brain connectivity in important neural pathways for emotion regulation - and that predicts symptoms of anxiety during adolescence."

In the study, the team of investigators utilized brain scans to show how teen girls with stressed out mothers during infancy displayed higher levels of stress. The scans demonstrated lower connections between the center of the brain, otherwise known as the amygdala, and the part of the brain that managed emotions, otherwise known as the ventromedial prefrontal cortex.

"Merging field research and home observation with the latest laboratory measures really makes this study novel," remarked Dr. Richard Davidson, a professor of psychology and psychiatry at the University of Wisconsin-Madison, in the statement. "This will pave the way to better understanding of how the brain develops, and could give us insight into ways to intervene when children are young."

The current study was based off a previous project that looked at 570 children and families who were enrolled in the Wisconsin Study of Families and Work (WSFW). The researchers looked at the impact of day care, maternity leave, and other factors related to family stress. With the current study, the researchers scanned the brains of 57 subjects (28 females and 29 males) to better understand the connection between the amygdala and the prefrontal cortex. Observing earlier results, the scientists found that the females had weaker connections and mothers had more stress that resulted in symptoms like depression, frustration, and marital conflict.

The team of investigators then questioned the teens on anxiety symptoms or stress they were currently facing. They discovered that there was a link between childhood stress and that elevated levels of cortisol in childhood could affect the development of the girls´ brains, causing there to be weaker connections between the amygdala and the prefrontal cortex.

"Our findings raise questions on how boys and girls differ in the life impact of early stress,'' continued Davidson, who also serves as a lab director at the university, in the statement "We do know that women report higher levels of mood and anxiety disorders, and these sex-based differences are very pronounced, especially in adolescence."

Based on the findings, the researchers believe that the project helps explain some of the changes that have happened from the first study to the current study.

"Now that we are showing that early life stress and cortisol affect brain development," concluded Marilyn Essex, a University of Wisconsin-Madison professor of psychiatry and co-director of the WSFW, in the statement. "It raises important questions about what we can do to better support young parents and families."